For many a family in England, Monday was one of the year's best days: the beginning in earnest of the six-week summer holiday, as the weekend gave way to the annual big break. Aeons of empty time lie ahead, stripped of timetables, uniforms and homework. True, today will be a little less lovely and the day after that outright challenging. But enjoy the present.

There is a way that there could be more first days of holidays, and fewer there's-nothing-to-do days. And if schools had four or five terms there would be other benefits too. Those last term-time weeks when younger children are too exhausted to learn, followed by a long break in which hard-won skills drain away, would be replaced by shorter terms, more alert kids and more frequent, shorter holidays. Keeping the cerebral muscle active is vital – and research has highlighted the corresponding danger of allowing young minds to fall into prolonged idleness. With the potential for two holidays in the summer period – late May to June, and then all of August – family getaways would be staggered and perhaps cheaper. Arranging childcare for shorter spells could be easier too.

Such arguments are too readily dismissed as narrow utilitarianism by well-heeled parents, who can afford to fork out whatever is needed to keep their own youngsters entertained. These same middle-class parents can ensure that learning doesn't stop at the school gate for their children. It is infants from the bottom of the heap who end up slipping back when studying stops, and poor teens who get into trouble when they are left to languish on the street for too long. Thus Frank Field MP alluded to the summer holiday problem in his recent report on poor children, and now it is Nottingham city council – which has a mightily deprived school intake – leading the way towards change, by consulting on a five-term year.

Nottingham's move was prompted by the perceived success of the local Djanogly academy, which already runs such a calendar. Michael Gove's free schools could encourage such innovations, but they also bring a related danger. If every institution simply sets its terms independently, families who rely on more than one school will be inconvenienced.

The 21st century seems a reasonable moment to overhaul a medieval legacy. While there is a certain nostalgia to a calendar that reflects agrarian rhythms – and the need for young hands to help with the harvest – consideration of how children actually learn must trump these whimsical charms. If the school calendar is finally emerging from the too-difficult tray, that is warmly welcome, but it is equally important that it does not end up in fragments.